Circulating tumour cells

Circulating tumour cells (CTCs) is a highly specialised and promising area of cancer research, which is being pioneered at the Ingham Institute in New South Wales. CTC research analyses cancer cells in the bloodstream to identify cancer biomarkers, or indicators to characterise the individual cancer of a patient.

Transcript

Norman Swan: Wouldn't it be nice if cancer could be diagnosed and treatment monitored without painful biopsies or expensive scans? Say with a simple blood test?

Well, that's becoming possible by detecting what are called circulating tumour cells.

That's what Associate Professor Therese Becker's working on at the Ingham Institute for Applied Medical Research at Liverpool Hospital in south-west Sydney.

Therese Becker: Circulating tumour cells are cells from solid tumours that get shed into the bloodstream. They can settle at other organs and form secondary tumours which we call metastases, and we can actually isolate those tumour cells, although they are very rare, we can isolate them from the blood and they give us a lot of information about the original tumour.

Norman Swan: So how rare are they?

Therese Becker: If we have 10 millilitres of blood we might have billions of red blood cells and white blood cells but only one or 10 or 100 circulating tumour cells at any given time.

Norman Swan: One in billions?

Therese Becker: So we have to isolate those cells from all the other normal blood cells.

Norman Swan: How do you do that?

Therese Becker: We attach magnetic beads specifically to the tumour cells via antibodies that recognise the surface of the tumour cells, and we literally can pull them by magnetic force.

Norman Swan: And what's the value of knowing that there are these circulating tumour cells in the blood?

Therese Becker: Simply knowing that those cells are there and knowing how many can be prognostic.

Norman Swan: So if you've got a particularly aggressive tumour it's likely to be throwing off more cells into the bloodstream.

Therese Becker: Yes. And we can monitor the numbers also in response to treatment. And once we have isolated those cells we can further analyse them into the molecular build of those cells and that will change the treatment which is best for the patient.

Norman Swan: And some people are talking about using them for diagnosis of cancer in the first place.

Therese Becker: Yes, but not every tumour has already started to shed cells. But there's good preliminary data, especially for really nasty cancers like pancreatic cancer. This is normally only diagnosed once the patient is already very ill, and patients that are at high risk because of familial background, if you could screen them for circulating tumour cells that may be very beneficial.

Norman Swan: So tell me about your work with circulating tumour cells and bowel cancer.

Therese Becker: We have one PhD student working on this and she is looking at response to treatment.

Norman Swan: Any results yet?

Therese Becker: That particular study will probably take two years to be finished.

Norman Swan: And what are you working on yourself?

Therese Becker: One study that I'm doing is in melanoma, and melanoma cells are different and I have found antibodies that we can couple to those magnetic beads that are very promising, and I have started to look at a few patients so far, and yes, it looks that we can isolate circulating melanoma cells now and tell the clinicians what treatment. We are often able to have those cells detected much earlier than a CT scan can detect a lump. And even those patients that are on our trials may benefit if we can say to the clinician, look, this patient has now a mutation that shows us he or she will not benefit from this drug alone. That can already, at least in the trial cases, change the treatment.

Norman Swan: Associate Professor Therese Becker is at the Ingham Institute for Applied Medical Research at Liverpool Hospital in Sydney.

Guests

Associate Professor Therese Becker

Ingham Institute for Applied Medical ResearchLiverpool, New South WalesUniversity of New South WalesUniversity of Western Sydney